Organic silicon compounds and method for making

ABSTRACT

Organic silicon compounds of formula (1) are novel.    &lt;IMAGE&gt;  (1) In the formula, wherein R1 and R2 are monovalent C1-8 hydrocarbon group, R3 is a C2-6 alkylene group or a C2-6 alkylene group containing at least one -C-O-C- linkage, R4 is a C1-6 alkyl group, Rf is a C1-15 perfluoroalkyl or perfluorocycloalkyl group or a C1-20 perfluoroalkyl or perfluorocycloalkyl group containing at least one -C-O-C- linkage, and n=0, 1 or 2, m=1 or 2, and k=2, 3 or 4. The organic silicon compounds are useful source materials for the manufacture of fluorinated polysiloxanes having solvent resistance, chemical resistance and release property.

This invention relates to novel organic silicon compounds having a fluorinated organic group and a dialkylamino group as side chains and a process for preparing the same.

BACKGROUND OF THE INVENTION

In the prior art, polysiloxanes containing fluorine atoms are well known as source materials for the manufacture of solvent resistant, chemically resistant rubber materials and source materials for the manufacture of mold release agents, water repellent agents and oil repellent agents.

A variety of polysiloxanes containing fluorine atoms have been proposed as well as compounds for introducing fluorine atoms into polysiloxanes. There is a need for a compound which can more easily and effectively introduce fluorine atoms into polysiloxanes such that the characteristics of fluorine atoms are exerted.

An object of the present invention is to provide an organic silicon compound which is useful as a source material from which polysiloxanes having improved properties including solvent resistance, chemical resistance and mold release properties are prepared in a relatively simple manner.

SUMMARY OF THE INVENTION

The inventors have found that a novel organic silicon compound having a fluorinated organic group and an organoaminoxy group as side chains as represented by formula (1) below is obtained by effecting a dehydrogenation reaction between a compound of formula (2) below and a diorganohydroxyamine. ##STR2## In formula (1),

R¹ and R² are independently selected from monovalent hydrocarbon groups having 1 to 8 carbon atoms,

R³ is an alkylene group having 2 to 6 carbon atoms or an alkylene group having 2 to 6 carbon atoms and containing at least one --C--O--C-- linkage,

R⁴ is an alkyl group having 1 to 6 carbon atoms,

Rf is selected from the group consisting of perfluoroalkyl and perfluorocycloalkyl groups having 1 to 15 carbon atoms and perfluoroalkyl and perfluorocycloalkyl groups having 1 to 20 carbon atoms and containing at least one --C--O--C-- linkage, and

letter n is equal to 0, 1 or 2, m is equal to 1 to 2, and k is equal to 2, 3 or 4.

This novel organic silicon compound includes a branching organoaminoxy group which is susceptible to condensation with a silanol compound. Therefore, fluorine atoms or a fluorine--containing organic group can be readily introduced into a silanol--containing organopolysiloxane by condensing the organoaminoxy group of the organic silicon compound with a silanol group of the organopolysiloxane. The organic silicon compound is effective as a chain extender when it contains two organoaminoxy groups, that is, difunctional, and as a crosslinking agent when it contains three or more organoaminoxy groups, that is, trifunctional or polyfunctional, as shown in schemes A and B.

A diorganoaminoxy group reacts with a hydroxyl group in accordance with the following formula.

    .tbd.SiONR.sub.2.sup.1 +HO--R→.tbd.SiOR+R.sub.2.sup.1 NOH

Then an organic silicon compound having a diorganoaminoxy group reacts with a polysiloxane having a silanol group, accomplishing chain extension or crosslinking.

Scheme A: Difunctional

Condensation reaction associated with the introduction of organic silicon compound into organopolysiloxane as a chain extender. ##STR3##

Scheme B: Trifunctional

Condensation reaction associated with the introduction or organic silicon compound into organopolysiloxane as a crosslinking agent. ##STR4##

Accordingly, the present invention in a first aspect provides a cyclic organic silicon compound of formula (1) which is useful as a source material for manufacturing a polysiloxane having a fluorinated organic group introduced into its side chain by condensing the compound with a silanol compound.

In a second aspect, there is provided a process for preparing an organic silicon compound of formula (1) by effecting dehydrogenation reaction between a cyclic compound of formula (2) and a diorganohydroxyamine.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1, 2 and 3 are charts illustrating the IR absorption spectra of the organic silicon compounds prepared in Examples 1, 2 and 3, respectively.

DETAILED DESCRIPTION OF THE INVENTION

The organic silicon compounds according to the present invention are of the following general formula (1). ##STR5## In formula (1),

R¹ and R², which may be the same or different, are independently selected from monovalent hydrocarbon groups having 1 to 8 carbon atoms, preferably 1 to 6 carbon atoms, for example, alkyl groups such as methyl, ethyl, propyl, butyl and hexyl groups, cycloalkyl groups such as a cyclohexyl group, alkenyl groups such as vinyl and allyl groups, and aryl groups such as a tolyl group.

R³ is an alkylene group having 2 to 6 carbon atoms, preferably 2 to 3 carbon atoms or an alkylene group containing one or more (preferably 1 to 6) --C--O--C-- linkages and having 2 to 6 carbon atoms, preferably 2 to 3 carbon atoms, for example, --CH₂ CH₂ -- and --CH₂ CH₂ OCH₂ --.

R⁴ is an alkyl group having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms.

Rf is selected from the group consisting of perfluoroalkyl and perfluorocycloalkyl groups having 1 to 15 carbon atoms, preferably 1 to 8 carbon atoms and perfluoroalkyl and perfluorocycloalkyl groups containing at least one (preferably 1 to 6) --C--O--C-- linkage and having 1 to 20 carbon atoms, preferably 5 to 14 carbon atoms. Examples of the Rf group are shown below. ##STR6##

Letter n is equal to 0, 1 or 2, m is equal to 1 or 2, and k is equal to 2, 3 or 4.

The organic silicon compounds of the invention can be prepared by effecting a dehydrogenation reaction between cyclic compound of formula (2) and diorganohydroxyamines of formula (3). ##STR7##

In formulae (2) and (3), R¹ to R⁴, Rf, n, m and k are as defined above.

The cyclic compounds of formula (2) can be prepared, for example, by agitating a mixture of a compound of the following formula (4) and a compound of the following formula (5) in the presence of tris(triphenylphosphine)-rhodium chloride, followed by simple distillation and rectification. ##STR8##

In formulae (4) and (5), R¹, Rf, n, m and k are as defied above.

Preferably, the compounds of formulae (4) and (5) are mixed such that 0.5 to 4 mol, especially 1 to 2 mol of the compound of formula (5) is present per mol of the compound of formula (4). The mixture is desirably agitated at a temperature of 50° to 200° C., especially 100° to 150° C. for about 2 to 24 hours, especially about 3 to 8 hours.

For obtaining the compound of the invention, the diorganohydroxyamine of formula (3) is added dropwise to the cyclic compound of formula (2). The amount of the diorganohydroxyamine of formula (3) added is preferably from 1 to 5 mol, especially from 1.1 to 1.5 mol per mol of .tbd.SiH in the compound of formula (2). The preferred reaction conditions include a temperature of 0° to 100° C., especially 10° to 30° C. and a time of about 1 to 8 hours, especially about 2 to 4 hours. This reaction can be carried out without a solvent by directly adding dropwise the diorganohydroxyamine of formula (3) to the cyclic compound of formula (2) although it is also possible to dissolve the cyclic compound of formula (2) in a solvent which does not impede the reaction, for example, benzene, toluene, xylene, n-hexane, cyclohexane and tetrahydrofuran, and adding dropwise the diorganohydroxyamine of formula (3) to the solution, if desired.

When the addition of diorganohydroxyamine is completed, the reaction solution is cooled down to room temperature and agitated for about 1 to 24 hours, preferably about 4 to 16 hours. Removal of the unreacted diorganohydroxyamine or a low-boiling fraction by stripping yields an organic silicon compound of formula (1). It is to be noted that since the organic silicon compound is hydrolyzable, a series of steps including addition of diorganohydroxyamine should preferably be carried out in an inert gas atmosphere such as nitrogen and argon.

The organic silicon compounds of formula (1) can condense with organopolysiloxanes having a silanol group under conventional condensation conditions as previously shown by schemes A and B, thus introducing fluorine atoms into the organopolysiloxanes.

EXAMPLE

Examples of the present invention are given below by way of illustration and not by way of limitation.

First described is the preparation of cyclic compounds of formula (2), from which organic silicon compounds of the present invention are prepared.

REFERENCE EXAMPLE 1

A 2-liter pressure vessel was charged with 600 grams (2.5 mol) of 1,3,5,7-tetramethylcyclotetrasiloxane, 1115 grams (2.5 mol) of perfluorooctylethylene, and 0.5 grams of tris(triphenylphosphine)rhodium chloride whereupon agitation was continued for 4 hours at 130° C. Subsequent simple distillation and rectification left 230.2 grams (yield 13%) of a fraction having a boiling point of 101° C./1 mmHg.

On analysis by ¹ H-NMR spectroscopy, IR absorption spectroscopy and elemental analysis, the fraction was identified to be a compound of the following formula (6). ##STR9##

REFERENCE EXAMPLE 2

A 2-liter pressure vessel was charged with 499 grams (3.0 mol) of 1-n-propyl-1,3,5,7-tetramethylcyclotetrasiloxane, 789 grams (3.0 mol) of perfluorooctylethylene, and 0.35 grams of tris(triphenylphosphite)rhodium chloride whereupon agitation was continued for 4 hours at 130° C. Subsequent simple distillation and rectification left 204.5 grams (yield 9%) of a fraction having a boiling point of 106°-108° C./1 mmHg. On analysis by ¹ H-NMR spectroscopy, IR absorption spectroscopy and elemental analysis, the fraction was identified to be a compound of the following formula (7). ##STR10##

REFERENCE EXAMPLE 3

A 2-liter pressure vessel was charged with 600 grams (2.5 mol) of a compound of formula (8), 1195 grams (2.5 mol) of a compound of formula (9), and 0.5 grams of tris(triphenylphosphine)rhodium chloride whereupon agitation was continued for 4 hours at 130° C. ##STR11## Subsequent simple distillation and rectification left 101 grams (yield 14%) of a fraction having a boiling point of 118° C./1 mmHg. On analysis by ¹ H-NMR spectroscopy, IR absorption spectroscopy and elemental analysis, the fraction was identified to be a compound of the following formula (10). ##STR12##

EXAMPLE 1

A 300-ml, three necked flask equipped with a reflux condenser connected to a calcium chloride tube, thermometer, dropping funnel connected to a gas inlet tube, and magnetic stirrer was charged with 150 grams (0.22 mol) of 1-(2-perfluorooctyl)ethyl-1,3,5,7-tetramethylcyclotetrasiloxane of formula (6) obtained in Reference Example 1. With stirring under nitrogen stream, 64.3 grams (0.72 mol) of diethylhydroxyamine was added dropwise to the flask. During addition, the flask was cooled with an ice water bath to an internal temperature of 20° to 40° C. At the end of addition of diethylhydroxyamine, the mixture was agitated for 12 hours at room temperature. Removal of a low-boiling fraction by stripping left 190 gams (yield 92%) of a product. Its IR absorption spectrum is shown in FIG. 1 and the results of its ¹ H-NMR spectroscopy and elemental analysis are shown in Tables 1 and 2. The product was thus identified to be an organic silicon compound of the following formula (11).

                  TABLE 1                                                          ______________________________________                                         Proton NMR                                                                     δ (ppm)                                                                  ______________________________________                                         0.30              s, --Si--CH.sub.3, 12H                                       1.00-1.25         m, --CH.sub.3, 18H                                           2.60-3.03         m, --CH.sub.2 --, 12H                                        ______________________________________                                    

                  TABLE 2                                                          ______________________________________                                         Elemental analysis                                                                      C    H       Si     F      O    N                                     ______________________________________                                         Calcd., %  33.0   4.9     11.8 34.1   11.8 4.4                                 Found, %   32.9   4.9     11.8 34.2   11.7 4.4                                 ______________________________________                                          ##STR13##

EXAMPLE 2

A 300-ml, three necked flask equipped with a reflux condenser connected to a calcium chloride tube, thermometer, dropping funnel connected to a gas inlet tube, and magnetic stirrer was charged with 150 grams (0.21 mol) of the compound of formula (7) obtained in Reference Example 2. With stirring under nitrogen stream, 41.1 grams (0.46 mol) of diethylhydroxyamine was added dropwise to the flask. During addition, the flask was cooled with an ice water bath to an internal temperature of 20° to 40° C. At the end of addition of diethylhydroxyamine, the mixture was agitated for 12 hours at room temperature. Removal of a low-boiling fraction by stripping left 178.1 grams (yield 94%) of a product. Its IR absorption spectrum is shown in FIG. 2 and the results of its ¹ H-NMR spectroscopy and elemental analysis are shown in Tables 3 and 4. The product was thus identified to be an organic silicon compound of the following formula (12).

                  TABLE 3                                                          ______________________________________                                         Proton NMR                                                                     δ (ppm)                                                                  ______________________________________                                         0.24              s, Si--CH.sub.3, 12H                                         1.00-1.31         m, --CH.sub.3, 6H                                            2.63-2.98         m, --CH.sub.2 --, 4H                                         0.91-1,15         m, --CH.sub.3, 6H                                            2.53-2.92         m, --CH.sub.2, 4H                                            ______________________________________                                    

                  TABLE 4                                                          ______________________________________                                         Elemental analysis                                                                      C    H       Si     F      O    N                                     ______________________________________                                         Calcd., %  33.0   4.9     11.8 34.1   11.8 4.4                                 Found, %   32.9   4.9     11.8 34.2   11.7 4.4                                 ______________________________________                                          ##STR14##

EXAMPLE 3

A 300-ml, three necked flask equipped with a reflux condenser connected to a calcium chloride tube, thermometer, dropping funnel connected to a gas inlet tube, and magnetic stirrer was charged with 150 grams (0.21 mol) of the compound of formula (10) obtained in Reference Example 3. With stirring under nitrogen stream, 61.7 grams (0.69 mol) of diethylhydroxyamine was added dropwise to the flask. During addition, the flask was cooled with an ice water bath to an internal temperature of 20° to 40° C. At the end of addition of diethylhydroxyamine, the mixture was agitated for 12 hours at room temperature. Removal of a low-boiling fraction by stripping left 205 grams (yield 94%) of a non-volatile matter. Its IR absorption spectrum is shown in FIG. 3 and the results of its ¹ H-NMR spectroscopy and elemental analysis are shown in Tables 5 and 6. The product was thus identified to be an organic silicon compound of the following formula (13).

                  TABLE 5                                                          ______________________________________                                         Proton NMR                                                                     δ (ppm)                                                                  ______________________________________                                         0.20              s, --Si--CH.sub.3, 12H                                       0.98-1.21         m, --CH.sub.3, 18H                                           2.59-3.00         m, --CH.sub.2 --, 12H                                        ______________________________________                                    

                  TABLE 6                                                          ______________________________________                                         Elemental analysis                                                                      C    H       Si     F      O    N                                     ______________________________________                                         Calcd., %  31.9   4.7     11.4 33.0   14.7 4.3                                 Found, %   32.0   4.5     11.3 32.8   14.9 4.5                                 ______________________________________                                          ##STR15##

The novel cyclic organic silicon compounds of the present invention have as side chains a fluorinated organic group and an organoaminoxy group which is susceptible to condensation with a silanol compound. Simply by carrying out condensation reaction between the organic silicon compound and a polysiloxane having a silanol group, fluorine atoms can be effectively introduced into the polysiloxane, imparting the characteristics of fluorine to the organopolysiloxane. Organic silicon compounds having two organoaminoxy groups act as chain extenders and those having three or more organoaminoxy groups act as crosslinking agents. Polysiloxanes which are chain extended or crosslinked with the organic silicon compounds of the invention exhibit characteristics inherent to fluorine introduced. The organic silicon compounds of the invention are useful as source materials for the manufacture of polysiloxanes and other organic resins which are required to have solvent resistance, chemical resistance, water repellency, oil repellency and lubricity.

The process of the present invention can produce such useful cyclic organosilicon compounds in a simple efficient manner.

While the invention has been described in what is presently considered to be a preferred embodiment, other variations and modifications will become apparent to those skilled in the art. It is intended, therefore, that the invention not be limited to the illustrative embodiments, but be interpreted within the full spirit and scope of the appended claims. 

We claim:
 1. An organic silicon compound of the following formula (1): ##STR16## wherein R¹ and R² are independently selected from monovalent hydrocarbon groups having 1 to 8 carbon atoms,R³ is an alkylene group having 2 to 6 carbon atoms or an alkylene group having 2 to 6 carbon atoms and containing at least one --C--O--C-- linkage, R⁴ is an alkyl group having 1 to 6 carbon atoms, Rf is selected from the group consisting of perfluoroalkyl and perfluorocycloalkyl groups having 1 to 15 carbon atoms and perfluoroalkyl and perfluorocycloalkyl groups having 1 to 20 carbon atoms and containing at least one --C--O--C-- linkage, and letter n is equal to 0, 1 or 2, m is equal to 1 or 2, and k is equal to 2, 3 or
 4. 2. A process for preparing an organic silicon compound of the following formula (1): ##STR17## wherein R¹ and R² are independently selected from monovalent hydrocarbon groups having 1 to 8 carbon atoms,R³ is an alkylene group having 2 to 6 carbon atoms or an alkylene group having 2 to 6 carbon atoms and containing at least one --C--O--C-- linkage, R⁴ is an alkyl group having 1 to 6 carbon atoms, Rf is selected from the group consisting of perfluoroalkyl and perfluorocycloalkyl groups having 1 to 15 carbon atoms and perfluoroalkyl and perfluorocycloalkyl groups having 1 to 20 carbon atoms and containing at least one --C--O--C-- linkage, and letter n is equal to 0, 1 or 2, m is equal to 1 or 2, and k is equal to 2, 3 or 4, said process comprising the step of effecting a dehydrogenation reaction between a cyclic compound of the following formula (2): ##STR18## wherein R¹, R², R³, Rf, n, m and k are as defined above and a diorganohydroxyamine of the following formula (3):

    R.sub.2.sup.4 NOH                                          (3)

wherein R⁴ is as defined above.
 3. The organic silicon compound of claim 1, wherein R¹ and R² are independently selected from the group consisting of methyl, ethyl, propyl, butyl, hexyl, cyclohexyl, vinyl, allyl and tolyl groups.
 4. The organic silicon compound of claim 1, wherein R⁵ is selected from the group consisting of an alkylene group having 2 to 3 carbon atoms and an alkylene group containing 1 to 6 --C--O--C-- linkages and 2 to 6 carbon atoms.
 5. The organic silicon compound of claim 1, wherein R³ is an alkylene group having 2 to 3 carbon atoms and containing 1 to 6 --C--O--C linkages.
 6. The organic silicon compound of claim 1, wherein Rf is selected from the group consisting of perfluoroalkyl and perfluorocycloalkyl groups having 1 to 8 carbon atoms and perfluoroalkyl and perfluorocycloalkyl groups containing 1 to 6 --C--O--C-- linkages and 5 to 14 carbon atoms.
 7. The organic silicon compound of claim 1, wherein Rf is a perfluoroalkyl or perfluorocycloalkyl group having 1 to 6 --C--O--C-- linkages.
 8. The process of claim 2, wherein the diorganohydroxyamine is added in an amount of from 1 to 5 mol per mol of .tbd.SiH groups in the compound of formula (2).
 9. The process of claim 8, wherein 1.1 to 1.5 mol of diorganohydroxyamine is used per mol of .tbd.SiH groups.
 10. The process of claim 2, wherein the dehydrogenation reaction is carried out at a temperature of 0°-100° C. for 1 to 8 hours.
 11. The process of claim 10, wherein the temperature is 10° to 30° C. and the time is 2 to 4 hours.
 12. The process of claim 2, wherein the diorganohydroxyamine is added dropwise to the compound of formula (2) and no solvent is used.
 13. The process of claim 2, wherein the diorganohydroxyamine is added dropwise to the compound of formula (2) which is dissolved in a solvent which does not impede the reaction. 